1. Field of the Invention
The present invention generally relates to a color adjustment method, and more particularly, to a color adjustment method for a display device.
2. Description of Related Art
As science and technology advances, higher displaying quality of video products is demanded. Typically, color adjustment methods of current display devices can be generally divided into intensity adjustment, hue adjustment, and saturation adjustment. It is well known that a relative high color relationship exhibits in a color space of red (R), green (G), and blue (B) color. Therefore, such RGB color space is often converted into an HSI color space, in which H represents hue; S represents saturation; and I represents intensity. For example, an RGB color space can be converted into an HSI color space in accordance with the following equations (1) through (3):
H=θ, if B≦G, and H=360−θ, if B>G, wherein θ=
                              cos                      -            1                          ⁢                  {                                                    1                2                            ⁡                              [                                                      (                                          R                      -                      G                                        )                                    +                                      (                                          R                      -                      B                                        )                                                  ]                                                    [                                                                    (                                          R                      -                      G                                        )                                    2                                +                                                      (                                          R                      -                      B                                        )                                    ⁢                                                            (                                              G                        -                        B                                            )                                                              1                      /                      2                                                                                  ]                                }                                    (        1        )                                S        =                  1          -                                    3                              (                                  R                  +                  G                  +                  B                                )                                      ⁡                          [                              min                ⁡                                  (                                      R                    ,                    G                    ,                    B                                    )                                            ]                                                          (        2        )                                I        =                              1            3                    ⁢                      (                          R              +              G              +              B                        )                                              (        3        )            
As such, the H, S, I factors can be easily adjusted in the HSI color space. Thereafter, H factor of each pixel thereof can be adjusted, for example, the H factor of each pixel is added up with 30. Similarly, I factor of each pixel thereof can also be adjusted, for example, the I factor of each pixel is added up with 30. In this situation, H, S or I factors of all pixels are adjusted in the meantime. However, it is not always necessary for all pixels of the image to be adjusted. Apparently, the aforementioned method unavoidably adjusts those did not need adjustment, and causes chrominance and luminance deviation thereto.
Accordingly, a solution thereof is proposed to adjust H, S, and I factors of sub-images of the image. However, this solution causes discontinuity between borders of the sub-images.